Question: Solve for $x$ and $y$ using substitution. ${-2x-4y = 10}$ ${x = 6y+11}$
Explanation: Since $x$ has already been solved for, substitute $6y+11$ for $x$ in the first equation. ${-2}{(6y+11)}{- 4y = 10}$ Simplify and solve for $y$ $-12y-22 - 4y = 10$ $-16y-22 = 10$ $-16y-22{+22} = 10{+22}$ $-16y = 32$ $\dfrac{-16y}{{-16}} = \dfrac{32}{{-16}}$ ${y = -2}$ Now that you know ${y = -2}$ , plug it back into $\thinspace {x = 6y+11}\thinspace$ to find $x$ ${x = 6}{(-2)}{ + 11}$ $x = -12 + 11$ ${x = -1}$ You can also plug ${y = -2}$ into $\thinspace {-2x-4y = 10}\thinspace$ and get the same answer for $x$ : ${-2x - 4}{(-2)}{= 10}$ ${x = -1}$